Hi there, this is probably a question that has been answered many times before, but I'm new to computer interfacing with electronics.
What I want to do is control a bank of relays with a USB port.
Ideally I'd be able to write a VB.net program to send data to this.
Does anyone know of such a board, as the main issue is that it has to work immediately. As in once I click a button on my PC I need the relay to react, not have to wait for the program to be uploaded again.
Thanks in advance, Daniel.

 

There are several choices. You will need to know things like the voltage and current being switched - not to mention the actual number of relays.

http://www.controlanything.com/Relay/Relay/USB_DEVICES

http://www.hobbyengineering.com/H2022.html

http://www.relaypros.com/mm5/merchant.mvc?Screen=CTGY&Store_Code=NCD&Category_Code=USB_relays